Treating hectograph bands



v ZJliLiiiu TRiiATiNG em croeaarn BANDS of West Virginia No Drag.

16 Claims.

The present invention relates to improvements in hectograph pads of the type usuallyemployed in hectograph machines and in their treatment prior to use.

The hectograph pads employed in hectograph or duplicating machines are usually in the form of relatively thin layers of gelatin mass mounted upon long strips of backing of paper or fabric to form along continuous band, which is rolled upon 10 a spindle or other supporting means for storage and in connection with its use in the duplicating,

surface of the gelatinous mass with a powder such as starch or talc to prevent the gelatinous copying mass from sticking to the back surface of the paper or fabric.

When powders are employed to prevent adhesion in this manner, the powder must be remoyed from the roll before it can be used by washing.

' or of air between the convolutions of the roll This is an operation requiring some time, involving the complete unrolling and rerolling of the band, and is sometimes found unpleasant or 30 occasionally omitted altogether by the user.

In accordance with the present invention, it has been found possible to provide the gelatinous mass of such a hectograph band with a coating which adequately prevents adhesion between the 35 gelatinous mass and the back of the fiber backing, the removal. of which, if desired, is much more easily accomplished than when powder is used; and which permits of copies being made on a first use of, the roll, even when the user 40 fails to remove the coating initially.

The coating, in, accordance with the present invention, may be applied after the formation of the hectograph band either before or during its roll ing upon a suitable support or spindle.

45 In accordance with the present invention, it has been'found that the provision of a thin film or coating of a water-soluble lower alkyl cellulose ether between the convolution of the roll ade-' quat ly prevents the undesired adhesion and so protectsthe surface of the copy Thus,

adhesion of the gelatinous mass to the backing of such bands may be'prevented by the application to the surface of the gelatinous mass of solutions of methyl-cellulose or the water-soluble- .ofi' ethyl-celluloses. These substances are preferably Ki Ill B. Whitmore, Oak liarh, lill.,-assignor to Ditto, Incorporated, Chicago, Ill, a corporation Application December 9, 1935, Serial No. 53,615

employed in dilute aqueous solution in which the proportion of the coating material may suitably be from 1 to 5% although somewhat stronger solutions, say up to may be employed, if desired. When so applied, adhesion of the gelatinous mass'to the backing is prevented and at the same time the'advantage is secured that bright copies can be made from the band without a preliminary washing to remove the coating material.

For example, I may employ an aqueous solution of methyl cellulose containing from 1 to 2% of the latter, applying it to the band prior to or during the rolling of the latter. A similar solution of a water-soluhlelethyl cellulose may be employed in the same manner. These coating.

agents which have been found effective in accordance with the present invention form solutions with surface tension characteristics which cause them to readily spread over and form a thin film on the surface of the gelatinous mass.

In the application of the coating solution to the band,-during the formation of the roll, it is preferred that the band be rolled on the spindle under tension while the coating llquidis being applied, the formation of pools or lakes of liquid being thereby avoided. For example, good results have been secured with a tension of two or three pounds per lineal inch of width. The provision of suitable tension upon the band during the rolling of the some also causes an eifectlve and even spreading of the coating solution and likewise prevents the retention between the con volutions of the roll of more than a very thin The present invention may also be employed in connection with relatively short or individual hectograph pads formed with the copy mass on a backing, to protect the surfaces of the pads and permit them being stacked upon one another.

Although the present invention has been described in connection with certain specific embodiments thereof, itis to-beunderstood that the details thereof arernot to be regarded as limitations upon the scope of the invention-except in so far as included in the accomp l l claims. u This application is a continuation in part of my prior application Serial No. 663,052, filed March 50 2'7, i933. j 3

I claim:

1. A hectograph-pad comprising a coating of duplicating material and a film of water-soluble alkyl cellulose on the duplicating surface.

2. A 'hectograph pad. comprising a coating of duplicating material and afilm oi methyl cellulose on the duplicating surface. j

3. A'hectograph pad comprising a gelatin coating and a film of a water-soluble alkyl cellulose on the surface of said gelatin coating. 1

4. A hectograph padcomprising agelatin coat ing and a film oi. methyl cellulose onthe-surface d gelatin coating. 3 a A hectograph pad comprising lelatin'wating and a film of water-soluble ethyl-cellulose tin-,

the surface of. said gelatin coating.

of a hectograph band, which method-comprises cellulose thereon.

'l. A method oftreati'ng the gelatiniaed surface of a hectograph band, which method comprises applying an aqueous solution of a water-soluble alkyl cellulose to said gelatinized surface to forma film of methyl cellulose thereon. c 8. A method of treating the gelatiniaed surface of a hectograph band, which method coniprises applying an aqueous solution of water-soluble -et lcellulosetosaid elatinizedsurfacetoform by g which comprises winding into a roll a band having a film of methyl cellulose thereon.

9. A hectograph band comprising a backing, a

30 coating of duplicating material thereon and an toa surfa'ce of the hand during thewinding operaintegral film of methyl cellulose upon the duplieating surface. I

10.. A hectograph band comprising a backing, a coating of duplicating'material thereon, and an as integral; film '61 a water-soluble alkyl cellulose upon the duplicating surface.

11. A hectographband comprising a backing, a oi duplicating material thereon, and an applying an aqueous solution of methyl cellulose to said gelatinired surface to form a film of methyl integral film ofwwater-soluble ethyl cellulose upon the duplicating surface. g

12. Aihectograph roll comprising a hectograph band wound into roll form, said band comprising a backing, a coating of duplicating material there on, and an integral film of methyl cellulose upon the duplicating surface.

13. A hectograph roll comprising a' hectograph band wound into roll form, said band comprising a backing, a coating of duplicating material there- 14. A vhectograph roll comprising a hectograph wound into roll form, said band comprising a backing, a coating of duplicating material thereon," and an integral film of water-soluble ethyl cellulose upon the duplicating surface. a

15. A hectograph band having on its duplicating surface an integral coating of a continuous film of -a material permeable to the duplicating inks whereby said band may be initially employed for duplicating purposes without removal of said material, said material'being adherent to the duplicating surface of the. band and non-adherent to the reverse side thereof. 16. A method of coating 9. hectograph band a backing and a gelatinized duplicating surface, applying an aqueous solution of methyl cellulose .10 on, and an integral film of a water-soluble alkyl 1 upon the duplicating surface. 8. A method of treating the'gelatinized surface 

